There is a solenoid operated device as is shown in FIG. 8 that drives a switchgear, for example, a breaker of a vacuum valve, to open and close a switch thereof.
In the solenoid operated device in the related art shown in FIG. 8, a closing coil 6 and a trip coil 7 are fixed to a yoke (fixed iron core) 9 via a bobbin 8. A braking iron 2 is also fixed to the yoke (fixed iron core) 9.
A plunger (movable iron core) 10 is disposed on and along center axes of the closing coil 6 and the trip coil 7 and forms a magnetic circuit together with the yoke (fixed iron core) 9 and the braking iron 2. The plunger (movable iron core) 10 is allowed to move by a magnetic force generated when a current is flown to the closing coil 6 and the trip coil 7 or by a trip spring 11.
A shaft 1 is fixed to a central shaft of the plunger (movable iron core) 10 and coupled to the switch of the switchgear by penetrating through the braking iron 2.
The trip spring 11 is disposed between the yoke (fixed iron core) 9 and the plunger (movable iron core) 10 and keeps pushing the plunger (movable iron core) 10 in an opening direction.
A stopper 14 is fixed to the yoke (fixed iron core) 9 via a stopper retainer 15. Also, a buffer 13 is attached to the plunger (movable iron core) 10. The stopper 14 collides with the buffer 13 during an opening operation so that an impact of collision is lessened.
A permanent magnet 5 is installed to the yoke (fixed iron core) 9 and a magnetic force of the permanent magnet 5 holds the plunger (movable iron core) 10 at a closing position against the trip spring 11.
Operations will now be described. When a current is flown to the trip coil 7, a magnetic force of the permanent magnet 5 decreases and a spring force of the trip sprig 11 forces the plunger (movable iron core) 10 to move in a direction in which the switch is opened. The plunger (movable iron core) 10 eventually stops by colliding with the stopper 14 and an opening operation is thus completed.
When a current is flown to the closing coil 6, a magnetic force forces the plunger (movable iron core) 10 to move in a direction in which the switch is closed. The plunger (movable iron core) 10 eventually stops by colliding with the braking iron 2 and a closing operation is thus completed.